1. Field of the Invention
The present invention relates to a portable facsimile apparatus operable by a rechargeable battery provided therein, and more particularly to such apparatus which informs an operator of the facsimile apparatus of attribute information concerning time period during which the facsimile is operable by the battery, the number of documents transmittable and the number of documents receivable on the basis of the quantity of electric charges remaining in the battery.
2. Description of the Related Art
Recently, a portable facsimile apparatus is proposed which has a rechargeable battery therein so as to be capable of transmitting and receiving a document at places where no AC power supply is available by the power fed by the battery.
In a facsimile apparatus of this kind, if the battery operation mode is selected, time available for transmission and/or reception, the number of documents transmittable and/or receivable are limited by the quantity of electric charges remaining in the battery.
However, since the facsimile apparatus of this kind has a structure in which the quantity of electric charges in the battery is detected only at the battery terminals, the state of the battery can be detected only immediately before the quantity of electric charges stored in the battery is substantially exhausted.
As discussed above, the conventional facsimile apparatus driven by a battery cannot previously supply the operator with information on how much time the apparatus can operate or how many documents it can transmit. Therefore, if the quantity of electric charges remaining in the battery is small, the voltage of the battery can abruptly fall below a predetermined value during communication, which is one of the drawbacks which degrade the reliability of the facsimile apparatus driven by a rechargeable battery.